"This was a freak of nature," Gov. Peter Shumlin said at a news conference Monday afternoon, where officials said rocks from a ledge fell onto the tracks.

One locomotive and one passenger car went over an embankment, and three other cars left the track but remained upright.

One of the injured was airlifted to Dartmouth-Hitchcock Medical Center in New Hampshire, officials said. Six others went to Central Vermont Medical Center with injuries including neck, back and shoulder pain and lightheadedness.

The Vermonter's 13-hour, 45-minute daily trip begins in St. Albans in northern Vermont. The route passes through cities including Burlington, Vermont, Springfield, Massachusetts, and New York, with D.C. as the final destination.

NBC affiliate WPTZ-TV said first responders said several cars of an Amtrak train derailed in the area of Route 12A and Bull Run Road in Northfield around 10:30 a.m. Monday.

Montpelier Fire Chief Robert Gowans told necn that there were no fatalities, but several people were transported to the hospital. Several other "walking wounded" are also being evaluated, he said.

"We got tossed around a bit," he said, and he saw a set of wheels roll by his window before his car flew across the tracks and up a small embankment before coming to a halt. The engine tumbled down a creek bed, he said.

The Federal Railroad Administration said in a tweet it is aware of the derailment and is sending investigators to the site.